Table 2.

Pulmonary chitosan carriers of drugs for the treatment of infectious diseases.

Code	Formulation and Preparation	Physicochemical Property	Aerodynamic Property	Cell Culture / Microbial Examination	In Vivo Performance	Remark	Reference
F1	Second line anti-tubercular drug “prothionamide” loaded chitosan nanoparticles are prepared by ionic gelation technique, followed by freeze-drying into dry powder inhalational formulation. To increase the flow property, prothionamide nanoparticles and anhydrous inhalable grade lactose are mixed (1:0.5, 1:1, 1:1.5 weight ratio etc.) manually using a geometrical dilution process.	Spherical particles of 314.37 ± 3.68 nm with a zeta potential value of 32.40 ± 1.04 mV are produced. The freeze dried nanoparticles are fluffy with a fair flow property. These nanoparticles are characterized by angle of repose, Carr’s index and Hausner ratio as 37.32˚, 17.43 % and 1.21 respectively. Their flowability improves through blending with lactose in 1:1 weight ratio, with angle of repose, Carr’s index and Hausner ratio of 29.25 ± 2.15˚, 9.8 ± 2.1 % and 1.11 ± 0.01 respectively. In vitro initial burst drug release followed by sustained release up to 96.91 % in 24 h is noted.	Emitted dose of 82.37 %, aerodynamic particle size of 1.76 μm, geometric standard particle size distribution of 1.96 and fine particle fraction of 81.19 % are reflected in Anderson cascade impactor study.	Nil	Animal study using single dose administration through mono-dose inhaler indicates that prothionamide nanoparticles loaded dry powder inhalation achieves Cmax 2.90 ± 0.28 μg/mL at Tmax 3 h. The dry powder inhalation of prothionamide nanoparticles maintains the plasma drug concentration above the minimum inhibitory concentration for a period more than 12 h, unlike pure drug which could only maintain for up to 3 h.	Stability study shows no significant changes in polydispersity index, zeta potential, drug entrapment efficiency and percent drug release. In vitro drug release finding is reflected in the in vivo pharmacokinetics study.	(Debnath et al., 2018)
F2	Isoniazid (INH) and rifampin (RMP) loaded genipin-crosslinked carboxymethyl chitosan (GEN-CS) nanogel is prepared using emulsion crosslinking method, washed with ultrapure water, ultra-filtered and vacuum dried.	Spherical homogeneous particles of 60 nm–130 nm with positive zeta potential are produced. The drug loads of INH and RMP are 92.7 μg/mg and 66.1 μg/mg, respectively. The particles show sustained drug release behaviour in the simulated lung fluid.	Nil	The nanoparticles have a relatively high anti-bacterial activity against multidrug-resistant tuberculosis at reduced cytotoxicity of drugs.	The GEN-CS/INH/RMP nanogel provides a predominant deposition of drug within the lung of animals when the nanogel particles are administered using a dried powder insufflator	To prepare GEN-CS nanogel for the encapsulation of INH and RMP, the GEN, which serves as the crosslinker, is 5000 to 10,000 times less cytotoxic than glutaraldehyde. The nanogel provides a safe and efficient administration of anti-tubercular drugs.	(Wu et al., 2018
F3	Rifampicin loaded octanoyl chitosan nanoparticles are produced by double emulsion solvent evaporation technique. Nanoparticles obtained are then lyophilized following the addition of 1 %w/v trehalose dehydrate as the cryoprotectant.	The octanoyl chitosan nanoparticles have smooth surface texture and spherical morphology, with diameter of 253 ± 19.06 nm, polydispersity index of 0.323 ± 0.059 and drug entrapment efficiency of 64.86 ± 7.73 %. Sustained drug release behaviour within 72 h of dissolution (73.14 ± 3.17 %) is noted.	The two-stage impinger analysis of the lyophilized rifampicin loaded octanoyl chitosan nanoparticles proceeds through dispersing the nanoparticles in 5 ml water and aerosolising from a jet nebulizer at 60 L/min. The nebulization efficiency is 77.04 ± 4.33 %, with a fine particle fraction of 43.27 ± 4.24 %.	Preliminary cytotoxicity studies of nanoparticles show no observable effect on cell viability over a period of 24 h on A549 cell lines.	Nil	The nanoparticles are physicochemically stable for 2 months. They show excellent aerosolisation profile and sustained drug release characteristics.	Petkar et al., 2018)
F4	Rifampicin-oleic acid first-generation nanoemulsion and its respective chitosan- and chitosan-folate conjugate-decorated second and third generation nanoemulsions are prepared by spontaneous emulsification technique.	The nanoemulsions have average droplet sizes of 40 nm–60 nm, with narrow polydispersity indices. They exhibit desirable pH, surface tension, viscosity, refractive index, density and viscosity attributes for pulmonary administration.	Nanoemulsions demonstrate more than 95 % aerosol output with an inhalation efficiency greater than 75 %. The aerosol output and inhaled fine particle fractions are primarily governed by the size and surface tension of nanoemulsions in an inverse relationship.	A significantly higher level of internalisation of nanoemulsion by alveolar macrophages is observed with third generation nanoemulsion than second generation nanoemulsion at 2 h of incubation due to dual receptor targeting of macrophage by means of chitosan and folate. The cell viability in NR8383 cells is above 80 %.	The intratracheal administration of the nanoemulsions depicts that first and third generation nanoemulsions attain higher plasma drug concentrations in the first hour due to higher levels of burst drug release. The second generation nanoemulsion demonstrates sustained plasma drug level in vivo.	The nanoemulsions are found to be safe with third generation nanoemulsion exhibiting higher cell internalization potential, moderately low plasma drug concentration, and higher lung drug content.	(Shah et al., 2017)
F5	Rifampicin loaded chitosan nanoparticles are prepared by ionic gelation using the probe sonication method. The pre-freezing of nanoparticles is conducted using freeze dryer at −40 °C for 1 h with 10 %w/v lactose solution as the cryo-protectant. The frozen nanoparticles are subjected to secondary drying at 20 °C for 24 h at 1 Pa pressure to obtain respirable powder. Further, the freeze-dried nanoparticles are adsorbed onto the inhalable lactose pre-blend (coarse lactose: Inhalac® 230 and fine lactose: Inhalac®400) in the weight ratio of 95:5.	Particles of 124.1 ± 0.2–402.3 ± 2.8 nm with drug entrapment efficiency of 72.0 ± 0.1 % and sustained drug release behaviour (In vitro release of 100 % pure drug within 12 h and approximately 90 % release of encapsulated rifampicin within 24 h) are produced.	Hausner ratio of nanoparticles is 1.22 ± 1.2. A fine particle fraction of 33.27 ± 0.87 % with a mass median aerodynamic diameter of 3.3 ± 0.18 μm are attained in Andersen cascade impactor analysis.	The percentage of J774 macrophage cell viability is higher with nanoparticles (80–90 %) than pure rifampicin (75–80 %) at the drug dosage of 0.125 mg/mL.	A marked increase in maximum plasma drug concentration is attained with dry powder inhalation of nanoparticles when compared against the oral commercial formulation.	The freeze-dried rifampicin nanoparticles act as a better targeted delivery system for lung drug deposition through direct organ-specific targeting than oral drug administration.	(Rawal et al., 2017)
F6	Isoniazid and rifampicin loaded chitosan nanoparticles are prepared by ionic gelation followed by spray drying processes.	Spherical particles with a size of 230 ± 4.5 nm, polydispersity index of 0.180 ± 0.021, drug encapsulation efficiency of 70.8 ± 6.6 % for rifampicin and 68.8 ± 7.0 % for isoniazid are produced. Initial burst (40 % to 50 % within 4 h) followed by late sustained drug release (90 % to 95 % up to 72 h) behaviour is attained.	Nil	Nil	Administration of nebulized nanoparticles for 28 days to M. tuberculosis infected mice results in undetectable mycobacterial colony forming unit in lung and spleen homogenates. A compressor nebulizer system is used in this study to administer drugs in aerosol to female Balb/c mice (20–30 g/mouse). Both drugs are detected in various organs (lung, liver, spleen and kidney) until 24 h post nebulization. The high lung drug concentration is attributed to drug retention via phagocytosis by macrophages.	The chitosan nanoparticles provide an effective drug targeting to macrophage-rich organ that is essential in tuberculosis treatment.	(Garg et al., 2015)
F7	Rifampicin loaded chitosan-polylactic acid-polyethylene glycol-gelatin nanoparticles are prepared by emulsion solvent evaporation technique.	Spherical and compact particles where size increases with increasing concentration of rifampicin (187 ± 10 nm to 214 ± 17.3 nm) and co-polymers (192 ± 8.5 nm to 234 ± 16.8 nm) are produced. The zeta potential increases from 21 ± 2.2 mV to 29 ± 1.6 mV with an increase in rifampicin concentration from 10 % to 50 %. The drug entrapment efficiency of nanoparticles improves with the use of copolymers where 96.8 % is achieved in the composite containing polylactic acid, polyethylene glycol and gelatin. The initial drug release is fast and declined thereafter.	Nil	Nil	Nil	The use of copolymers is deemed beneficial in drug entrapment within the nanoparticulate system, and it provides a slow late phase of drug release.	(Rajan & Raj, 2013)
F8	Isoniazid loaded chitosan nanoparticles are prepared by ionic gelation method. These nanoparticles are co-spray dried with lactose, mannitol and maltodextrin with or without leucine to produce inhalable microparticles containing the drug loaded nanoparticles.	Spherical, hexagonal and rod shaped particles with a size of 449.1 ± 0.3 nm, a polydispersity index of 0.24 ± 0.03, a zeta potential of 38.9 ± 1.0 mV, a drug loading of 6.00 ± 0.18 % and a drug encapsulation efficiency of 17.0 ± 2.0 % are produced. Initial burst release of isoniazid (40 % to 55 % in 4 h) followed by sustained release up to 6 days are noted. Co-spray drying of nanoparticles with lactose produces small particles (3 μm–5 μm). The use of mannitol and maltodextrin leads to the formation of larger particles (more than 10 μm) due to aggregation of fine particles.	The powders were aerosolised in air stream of 60 l/min for 4 s using Cyclohaler. The in vitro deposition of the aerosolised drug is investigated using a twin stage impinge. The emitted dose of 46 % to 90 % and fine particle fraction of 7.05 % to 45 % are attained.	The minimum inhibitory concentration of tests using isoniazid solution is about 16 times higher than that of employing isoniazid loaded nanoparticles. The nanoparticles exhibit a higher anti-bacterial activity against Mycobacterium avium Intracellulare than S. aureus and P. aeruginosa.	Nil	The fine particle fraction of lactose containing powders is higher than mannitol and maltodextrin containing powders. The latter experience particle adhesion onto the capsule and inhaler wall thereby negating their aerosolization and inhalation processes. The introduction of leucine improves the fine particle fraction of drug aerosolized from all formulations due to the production of spherical particles with rough surface. This surface roughness could improve the aerosolisation capability of the spray dried powders by reducing cohesion between particles.	(Pourshahab et al., 2011)
F9	Isoniazid loaded chitosan microparticles, with or without prior tripolyphosphate crosslinking, are prepared by spray drying method.	The microparticles are produced in high yields (30.5 % to 46.3 %) and drug encapsulation efficiencies (> 80 %), with positive zeta potential (+17.7 mV–29.8 mV) and particle size ranging between 3.2 μm and 3.9 μm. Crosslinked chitosan microparticles exhibit a slower drug release than non-crosslinked microparticles.	Nil	The chitosan microparticles exhibit mucoadhesive property with mucin in vitro and oral mucosal fragment of pork ex vivo. 50–190 kDa chitosan microparticles do not exert cytotoxic effect against alveolar macrophages whether they are modified by drug or crosslinking agent.	Nil	Incubation of chitosan microparticles with peritoneal macrophages indicate that the cytotoxicity decreases in the presence of drug or crosslinking agent.	(Oliveira et al., 2017)
F10	Doripenem loaded chitosan microparticles with different lactose, trehalose, and l-leucine concentrations are prepared by ionotropic gelation and spray drying methods.	Surface-porous particles of 3.8–6.9 μm that are spherical and corrugated in shape are produced. The drug encapsulation efficiency varies between 78 % and 86 %. The particles exhibit burst drug release in the first 3 h followed by a controlled release of doripenem over 24 h.	Emitted dose of microparticles containing leucine is higher (98 %). These particles are characterised by a mass median aerodynamic diameter of 4.11 μm, a geometric standard particle size distribution of 2.11 and a fine particle fraction of 27.6 %.	The viability of cells treated with drug loaded microparticles at 0.5 mg/mL and 10 mg/mL concentrations varies from 70 % to 90 % in human Caucasian lung adenocarcinoma (Calu-3) cell line.	Nil	The microparticles are characterised by higher fine particle fraction values than commercial dry powder inhalational products (10 % to 20 %). Doripenem loaded chitosan microparticles can be employed in the local treatment of respiratory diseases such as pneumonia.	(Yildiz-Peköz et al., 2018)
F11	Dapsone loaded solid microcapsules are prepared by pre-emulsification of dapsone with chitosan and raspberry oil in the presence of stabilizers, using a rotor-stator system followed by high-pressure homogenization and spray drying.	The mean size of the emulsion globules is 430 nm, generating spray dried microcapsules with spherical shape and diameter (D4,3) of 7 μm. Sixty % of drug are released in 3 h of dissolution, and almost all content of drug are released in 24 h.	The Anderson cascade impactor analysis of microcapsules at 60 L/min for 4 s depicts a mass median aerodynamic diameter of 4.7 μm, a span of 1.21, and a fine particle fraction of 50 %.	Nil	The acute toxicity is evaluated on the basis of lactate dehydrogenase, alkaline phosphatase and total protein in the bronchoalveolar lavage fluid of animal model, that depicts that the drug loaded microcapsules exert a lower level of toxicity than the neat drug.	The pulmonary administration of dapsone loaded microcapsules appears to be a promising treatment alternative to eradicate Pneumocystis carinii in association with pneumonia.	(Ortiz et al., 2015)
F12	Levofloxacin loaded swellable chitosan microspheres are prepared by spray drying method with glutaraldehyde as crosslinker.	The microspheres show almost immediate drug release.	The microspheres are characterised by an emitted dose of 90 %, a mass median aerodynamic diameter of 5 μm and a fine particle fraction of 30 %.	The anti-bacterial efficacy of microspheres against the bacterial isolates of P. aeruginosa is equivalent to free levofloxacin.	Nil	The microspheres are envisaged to be able to reach the conductive zone of the respiratory tract where the P. aeruginosa are located.	(Gaspar et al., 2015)